A sophisticated hacking campaign launched from computers in China burrowed deeply into satellite operators, defense contractors and telecommunications companies in the United States and southeast Asia, security researchers at Symantec Corp said on Tuesday.

Symantec said the effort appeared to be driven by national espionage goals, such as the interception of military and civilian communications.

Such interception capabilities are rare but not unheard of, and the researchers could not say what communications, if any, were taken. More disturbingly in this case, the hackers infected computers that controlled the satellites, so that they could have changed the positions of the orbiting devices and disrupted data traffic, Symantec said.